This application relates to a scroll compressor wherein a temperature responsive valve controls an oil bleed from a high pressure chamber to a suction chamber, such that hot oil can be selectively delivered to a motor protection switch for the compressor motor.
Scroll compressors are becoming widely utilized in refrigerant compression applications. In a scroll compressor, a pair of scroll members each have a base and a generally spiral wrap extending from its base. The wraps interfit to define compression chambers. One of the two scroll members is caused to orbit relative to the other by an electric motor driving a shaft. As the two orbit, the size of the compression chamber decreases and an entrapped refrigerant is compressed.
In one known type of scroll compressor, the motor and the scroll members are received within a sealed housing shell. Some structure separates the interior of the sealed housing into a high pressure side and a suction pressure side. The refrigerant is delivered into the suction pressure side, and is allowed to pass over the electric motor cooling the electric motor. Historically, the separation of the interior of the housing shell into the two chambers was done by a separate separator plate. More recently the non-orbiting scroll member has been utilized to provide the separation between the two sides.
In scroll compressors having a separator plate, a technique was utilized wherein a temperature responsive valve selectively controlled the flow of oil onto a temperature sensitive safety switch for the electric motor. If the scroll compressor became too hot, the switch would open and hot oil would be allowed to drop onto the safety switch and the motor would stop. This prevents damage to the compressor when an undesirable occurrence, such as a loss of charge of refrigerant, occurs.
The prior art and its oil valve did not extend across the separator plate, and thus only returned oil from one portion of the suction pressure side to another portion. Oil which traveled with the refrigerant and into the discharge pressure chamber was not easily returned to the compressor sump, especially when there was a lesser charge of refrigerant, such in a loss of charge situation.